The present invention relates to a calibration apparatus and calibration method thereof, and more particularly to a calibration apparatus that calibrates a current of a current generator to obtain a deviation of a passive element in the integrated circuit and a method thereof.
Passive elements, such as resistors and capacitors, are critical elements in an integrated circuit. For example, a reference current can be generated by coupling an internal resistor having a resistance R to the output of a bandgap reference circuit, in which the output voltage of the bandgap reference circuit is Vbg. Therefore, the reference current of Vbg/R is obtained. However, the process variation may cause a large deviation upon the internal resistor and consequently vary the required current value of the reference current. In addition, an internal capacitor can be utilized for implementing a filter in the integrated circuit. In other words, the accuracy of the passive element may greatly influence the function of the integrated circuit. Therefore, a mechanism is required to acquire the deviation of passive elements in the integrated circuit.